All Answers

+118725

I didn't know that you had already answered when I lodged mine Chris. The lodgement times are only 2 minutes apart.
There you go - great minds doing great things at the same time.

MelodyMar 22, 2014

+118725

Is there anything that i can help you with now Stu?
Are you based in the NSW country somewhere?
Melody.

MelodyMar 22, 2014

+118725

Phida:
How do you Solve this?
2(x+3) - 2x^2(x+3) = 0
In my answer sheet they rewrite it to (x+3) * (2-2x^2) = 0
Im unsure what happens to the other (x+3)
Thank you in advance !

Hi Phida,
That is a good well presented question.
2(x+3) - 2x ²(x+3) = 0

Here is a slightly different question that might help you to understand.
Factorise this

2g - 2x ²g
The g is a common factor so it can be factorised to
g(2-2x ²)
so
2 g - 2x ² g = g(2-2x ²)
Do you completely understand this? If not then let me know!
Now, in your question, it is not g it is (x+3) but it can still be factorised out in the same way.

2 (x+3) - 2x ² (x+3) = (x+3)(2-2x ²)
SO
2 (x+3) - 2x ² (x+3) =0
(x+3)(2-2x ²) = 0
If I had done it I would have factorised out the 2 as well but it doesn't matter.
Is that enough help do do you want some more?

MelodyMar 22, 2014

+130561

How do you Solve this?
2(x+3) - 2x^2(x+3) = 0
In my answer sheet they rewrite it to (x+3) * (2-2x^2) = 0
Im unsure what happens to the other (x+3)

They (almost) took the greatest common factor, (x + 3), out of both terms......... !!!!

We can also take a "2" out !!!

Doing this, we get

2 * (x + 3) * (1 - x^2) = 0

We can get rid of the 2 by dividing through, so this becomes

(x + 3) * (1 - x^2) = 0

To solve, set each factor = 0

The first one is easy

x + 3 = 0

Subtracting 3 from both sides, we get

x = -3 and that's one solution

Now, setting the other factor to 0 we get

1 - x^2 = 0

This can be factored as

(1 - x) * (1 + x) = 0

And setting these two things to 0 (as before), we get the other two solutions of 1 and -1

Hope this helps

CPhillMar 22, 2014

#78

+118725

Hi Everyone,
Today was another quiet Friday/Saturday. Still as always there were some great answers forth coming. These answers were provided by CPhill, Samgelinas, alan guest, Bertie, Stuff, and Rom. Thank you all.

I have been asked to give some guidance on question and answer presentation. I will do my best.

1) Make full use of all the buttons above the smilies. I have done a separate post on this and I spoke about it only yesterday. This is a quote from yesterday’s wrap:
"Could everyone please read this post and learn from it or add to it if possible." http://web2.0calc.com/questions/viewtopic.php?f=2&t=9695&p=21263#p21263

2) We are slowly learning how to bring Web2.0 calculator outputs into the forum. This is also covered in the above post. Alan was extending my knowledge today. Thanks Alan. He displayed a trinomial factorisation, an indefinite integral and a definite integral all outputted from the web2.0 calc. I have included these in a new post in the above thread. The input is written under the output so they should be self explanatory but if they aren't then let me know and I will help you work it out.

3) If you want to add symbols such as an integral sign, these can be copied from other places and pasted in. Sometimes I will open a new window and then open this page within it http://www.rapidtables.com/math/symbols/Basic_Math_Symbols.htm. It is a list of mathematical symbols. I let the symbols occupy half the screen and the post occupy the other half so that I can gather the symbols as I need them. You can also do this using the Microsoft character map but I often find the symbols in there to be very elusive. I am sure there are many other places that symbols can be gleaned from.

4) I very often include attachments in my posts. These are almost always collected straight from other screens using the Snipping Tool. The Snipping Tool is included automatically in Windows 7 and I assume in Windows 8. I save the output (as a jpg) and then upload it to the forum. I file these under date and name so they are always very easy to find. The name of the upload is included in the post under the attachment so you can see how I store it if you want to. Anyway, I just upload these jpg files as attachments. This might sound like an ordeal but once you get used to it is really very simple.

5) Sometimes I will write a program in LaTex. I will then use the Snipping Tool, to snip the output that I want, and upload it as an attachment. You can save the output directly from the program but it is stored as a pdf file and these cannot be uploaded as attachments. I suppose that they could be converted to an acceptable file form using some conversion program. I have wondered about this because if the output was too long my method would not work very well. So far it has not really been a problem so I have not worked it out. Maybe someone would like to add input here.
Some people probably use MathType instead of LaTex for this purpose.

6) When I draw geometry things, I use GeoGebra which is a free download. This also has a simple version of latex built into it. (I think you can actually turn the picture into LaTex code but I haven’t worked this one out yet.) You don't have to use the LaTex but it is handy sometimes. Again, I collect the output using the Snipping Tool. My knowledge of GeoGebra is not great, I am using the ‘trial and error when I need it’, method of learning.
There are many other geometry programs out there this is just the one I use.

7) We should always try to use the Web2.0 calc output whenever possible but sometimes I also use 'Wolfram|Alpha calculator' and 'Desmos Graphing Calculator'. Both of these are very powerful tools. The output of these can be bought in via the Sniping Tool or via the web address.

8) This is not really relevant in the body of the forum but if you want to send someone a picture in the private message section. I don’t think that you can upload an attachment. I would use a tool called Gyazo for this. It is another free download. It is used like the snipping tool only instead of storing the image as a jpg it stores it in the ‘cloud’ and supplies you with the web address.

I don’t understand hardly any of this technology but it is all very cool.

That is all I can think of at the moment. I would love for other people to further extend my knowledge in these areas.

It is weekend for everyone now.
Enjoy what is left of it.
Melody.

MelodyMar 22, 2014

+118725

bump

MelodyMar 22, 2014

+118725

bump

MelodyMar 22, 2014

+118725

asley8273:
how do i do a problem like this 1/2(w-4)

You have asked 1/2 * (w-4) = (w-4)/2

is this what you mean or is the real question 1/[2(w-4)] ?

You need to use brackets to get the question correct and to make sure that we understand what you are asking.

MelodyMar 22, 2014

+118725

Guest:
How do you factor expressions in the form ax (to the second power) + bx + c?

We could help more if you give us an actual example.

Anyway,
Try working through this page.

http://www.mathsisfun.com/algebra/factoring-quadratics.html

MelodyMar 22, 2014

+118725

Hi Bertie,

Considering that we don't have Latex here, I think that you have done a very good job of presenting this.
I do have a couple of little suggestions. I think that I would like to include other people in this so I will talk about it in my nightly wrap.
I'll do this either tonight or in the very near future.

Welcome to the forum Bertie I sent you a private message to welcome you ages ago, when you first joined up. I know that you haven't collected it yet.
I wrote a lot more here but I have decided to include it in tonight's wrap instead. Other new people need to know about the mail system as well.

Thanks you for this post. I am so glad that you decided to join in.
Melody.

edit.
The message information is not in tonight's wrap afterall - I'll probably include it tomorrow!

MelodyMar 22, 2014

+118725

Alan:
pmcclure:
is there a way to factor polynomials on this calculator? thanks

you can try using the keyword "factor". For example:
factor(x^2-2x-3)

Thank you Alan.
I have just added this to the 'Buttons above the smilies' thread. Maybe I should rename that thread. I'll think about it.
Anyway thanks for all you fantastic input. I really appreciate it.

MelodyMar 22, 2014

+118725